PHENANTHRENES, DIHYDROPHENANTHRENES AND BIBENZYLS FROM THE ORCHID BULBOPHYLLUM-VAGINATUM

Two new phenanthrenes (4,9-dimethoxyphenanthrene-2,5-diol and 4,6-dime thoxyphenanthrene-2,3,7-triol) and two new 9,10-dihydrophenanthrenes ( 4-methoxy-9,10-dihydrophenanthrene-2,3, and 6-dimethoxy-9,10-dihydroph enanthrene-2,3,7-triol), along with six known phenanthrenes, four know n 9,10-dihydrophenanthrenes no known bibenzyls and the triterpenoid fr iedelin were isolated and characterized from the hexane extract of the orchid Bulbophyllum vaginatum. The structures of these compounds were determined by spectroscopic analyses. Copyright (C) 1996 Elsevier Sci ence Ltd